The thread you've got going elsewhere mentions that your design is for OS46 engines. The props they run are in the 10-12" range. Placing engines like that 7.5" apart is what you plan?
What do you mean by "engine loss p-factor"?
The thread in the other forum gives the impression you've got engine out yaw confused with p-factor. You do understand that p-factor is something that happens when a prop encounters the airflow at some angle other than perpendicular. And the unbalanced thrust has way more effect than the incidental p-effect? The imbalance of thrust from the engine out is way more a problem than any extra effect from the p-effect that happens while the airplane is being yawed by the operating engine.
I thought when you loose an engine and the p-factor sum was change by the loss (change in p-factor) was what produced the yaw difference along with the thrust being of center. I understand what you are saying. I didn't express it correctly, because if I loose an engine where the p-factor is working against the other engines p-factor it will be a different yaw effect loosing visa-versa. Thank You for clarifying.
I am planning on 3 or 4 blade custom prop. (not blade overlap :-)
I appreciate the questions, for I have much to learn.
Ionikios